Salzebullioskopie II Die Gültigkeit des salzebullioskopischen und salzkryoskopischen Grenzgesetzes in verschiedenen Inertsalz‐Fremdsalz‐Systemen

Abstract

AbstractThe vapor pressure of a saturated salf solution (the salt acting as inert electrolyte) is lowered by foreign solutes by an amount which is proportional to the molal concentration of the foreign solute. Any ion not in common with the inert electrolyte is acting as a foreign solute. This effect is used in salt ebullioscopy, a new procedure for the determinaton of the relative weights of ions which has been described recently [2]: The number ν of foreign ions per formula unit of the solute is determined experimentally and permits the evaluation of relative ionic weights. It was found that the apparent number ν(m2) of foreign ions per mole of solute determined at different concentrations of the solute sows a linear dependence on concentration: v(m2) = νo + N · m2. The linearity has been tested on 31 systems differing in the pair foreign salt –inert salt. The largest deviation of νo from the true value of ν was 0,1. It is shown theoretically that the slope N is the sum of a stöichiometric term N*, and of a term caused by the change of the activity coefficient γ2 of the solute. Therefore, γ2 can be calculated from (N – N*). The nuclearity (n = 1/ν) of the antimony complex in the compound potassium antimony tartrate was found to be 2.